'northernmost' originates from Old English, specifically the word 'norþerne,' where 'norþ' meant 'north' and '-ern' was a suffix indicating direction.

'norþerne' transformed into the Middle English word 'northerne,' and eventually became the modern English word 'northernmost.'

Initially, it meant 'pertaining to the north,' but over time it evolved into its current meaning of 'situated furthest to the north.'